Prior art water pressure regulators, such as the ones described and illustrated in U.S. Pat. Nos. 5,967,167 and 6,202,682, have a regulating valve, positioned in an outlet or reduced pressure chamber, connected to a flexible diaphragm. Increased water pressure in the outlet pressure chamber causes the flexible diaphragm to move, and thus the regulating valve to move, such that the regulating valve prevents pressurized water from a supply source from entering the outlet pressure chamber. Conversely, decreased water pressure in the outlet pressure chamber causes the flexible diaphragm to move, and thus the regulating valve to move, such that the regulating valve allows pressurized water from the supply source to enter the outlet pressure chamber.
Such water pressure regulators have a number of disadvantages/drawbacks. For instance, these water pressure regulators rely on the force of the water in the outlet pressure chamber to push down on a diaphragm in order to prevent pressurized water from the supply source from entering the outlet pressure chamber. However, when the regulating valve closes off the flow of pressurized water from the supply source to the outlet pressure chamber, the water flowing from the supply source continues to flow toward the outlet pressure chamber and the force thereof can cause the regulating valve to undesirably and repeatedly open and close (i.e., water hammer), because it is located within the outlet pressure chamber. Water hammer can result in wear and tear on the regulating valve and the diaphragm and, further can result in possible leakage in the downstream watering lines, i.e., at the individual watering valves (nipples). Further, the design of prior art regulating valves can cause them to begin to lose their effective seals over time due to build-up of foreign material on the regulating valve; this can also decrease the life of the sealing mechanism due to wear.